According to a luminous container for a high pressure discharge lamp described in Japanese patent publication 10-125230A, a molded body for a main body of a tube and a ring-shaped sealing member for the end portion are separately produced, and the two kinds of the molded bodies are assembled to produce an assembly. The assembly is then sintered to produce a container for sealing metal halide. In the process, the sintering shrinkages of both molded bodies are designed so that the outer diameter of the sintered body of the molded body for the sealing member for the end portion is larger than the inner diameter of the molded body for the main body for the tube, if each of the molded bodies would have been sintered alone. During the sintering, a clamping force is applied from the main body of the tube toward the sealing member for the end portion so that both sintered bodies are bonded in good manner to preserve excellent air-tightness.
For example, according to a luminous container for a high pressure discharge lamp listed in Japanese patent publication 10-125230A, a ring-shaped sealing member is pressed onto the end portion of the luminous vessel and an electrode member is inserted into a through hole of the sealing member. The sealing member is made of a cermet and the luminous vessel is made of a ceramic material such as alumina. The molded body for the sealing member is fixed in the opening in the end portion of the molded body for luminous vessel, and the molded bodies are then sintered to shrink them. In this process, it is designed that the shrinkage percentage of the luminous vessel is made larger than that of the sealing member. It is thus possible to generate compressive force from the luminous tube toward the sealing member to fix the sealing member in air-tight manner. A metal electrode member is inserted into the opening of the sealing member to seal the sealing member and electrode member in air-tight manner.